# -*- coding: utf-8 -*-
"""
搜索服务层

功能说明:
- 提供统一的搜索服务接口
- 集成秘塔AI搜索API
- 处理搜索结果的缓存和存储
- 提供搜索历史管理功能

作者: MetasoCreator Team
创建时间: 2025-08-19
"""

from typing import Dict, Any, List, Optional
from datetime import datetime
import hashlib
import json

from .metaso_client import get_metaso_client, MetasoAPIError
from config.config import Config


class SearchService:
    """
    搜索服务类
    
    提供完整的搜索功能，包括:
    - 网页搜索
    - 结果缓存
    - 搜索历史记录
    - 结果格式化
    """
    
    def __init__(self):
        """
        初始化搜索服务
        """
        self.metaso_client = get_metaso_client()
        
        # TODO: 初始化数据库连接和缓存
        # self.db = get_database_connection()
        # self.cache = get_redis_connection()
        
    def search(self, query: str, user_id: Optional[str] = None, 
               scope: Optional[str] = None, include_summary: Optional[bool] = None,
               page: Optional[int] = None, size: Optional[int] = None) -> Dict[str, Any]:
        """
        执行搜索查询
        
        Args:
            query: 搜索查询关键词
            user_id: 用户ID，用于记录搜索历史
            scope: 搜索范围 (webpage, document, scholar, podcast, image, video)
            include_summary: 是否包含摘要信息
            page: 页码（与size互斥）
            size: 每页大小（与page互斥）
            
        Returns:
            Dict: 格式化的搜索结果
        """
        try:
            # 检查API密钥是否配置
            if not hasattr(self.metaso_client, 'api_key') or not self.metaso_client.api_key:
                return self._create_error_response("秘塔AI API密钥未配置，请检查环境变量 METASO_API_KEY")
            
            # 构建搜索参数
            search_params = {
                'scope': scope,
                'include_summary': include_summary,
                'page': page,
                'size': size
            }
            
            # 检查缓存
            cache_key = self._generate_cache_key(query, search_params)
            cached_result = self._get_cached_result(cache_key)
            
            if cached_result:
                return cached_result
            
            # 调用秘塔API进行搜索
            raw_result = self.metaso_client.search(
                query=query,
                scope=scope,
                include_summary=include_summary,
                page=page,
                size=size
            )
            
            # 格式化搜索结果
            formatted_result = self._format_search_result(raw_result, query)
            
            # 缓存结果
            self._cache_result(cache_key, formatted_result)
            
            # 记录搜索历史
            if user_id:
                self._save_search_history(user_id, query, formatted_result)
            
            return formatted_result
            
        except MetasoAPIError as e:
            return self._create_error_response(f"搜索服务暂时不可用: {str(e)}")
            
        except Exception:
            return self._create_error_response("搜索服务发生未知错误")
            
    def get_search_suggestions(self, partial_query: str, limit: int = 5) -> List[str]:
        """
        获取搜索建议
        
        Args:
            partial_query: 部分查询词
            limit: 建议数量限制
            
        Returns:
            List[str]: 搜索建议列表
        """
        try:
            # 检查API密钥是否配置
            if not hasattr(self.metaso_client, 'api_key') or not self.metaso_client.api_key:
                if len(partial_query) >= 2:
                    suggestions = [
                        f"{partial_query}是什么",
                        f"{partial_query}怎么样",
                        f"{partial_query}的作用",
                        f"{partial_query}教程",
                        f"{partial_query}最新消息"
                    ]
                    return suggestions[:limit]
                return []
            
            # TODO: 实现基于历史搜索的建议功能
            suggestions = []
            
            if len(partial_query) >= 2:
                common_patterns = [
                    f"{partial_query}是什么",
                    f"{partial_query}怎么样",
                    f"{partial_query}的作用",
                    f"{partial_query}教程",
                    f"{partial_query}最新消息"
                ]
                suggestions = common_patterns[:limit]
            
            return suggestions
            
        except Exception:
            return []
            
    def get_search_history(self, user_id: str, limit: int = 20) -> List[Dict[str, Any]]:
        """
        获取用户搜索历史
        
        Args:
            user_id: 用户ID
            limit: 历史记录数量限制
            
        Returns:
            List[Dict]: 搜索历史列表
        """
        try:
            # TODO: 从数据库获取搜索历史
            return []
            
        except Exception:
            return []
            
    def clear_search_history(self, user_id: str) -> bool:
        """
        清除用户搜索历史
        
        Args:
            user_id: 用户ID
            
        Returns:
            bool: 是否成功清除
        """
        try:
            # TODO: 从数据库删除搜索历史
            return True
            
        except Exception:
            return False
            
    def _generate_cache_key(self, query: str, options: Optional[Dict] = None) -> str:
        """
        生成缓存键
        
        Args:
            query: 搜索查询
            options: 搜索选项
            
        Returns:
            str: 缓存键
        """
        cache_data = {
            'query': query.lower().strip(),
            'options': options or {}
        }
        cache_string = json.dumps(cache_data, sort_keys=True)
        return f"search:{hashlib.md5(cache_string.encode()).hexdigest()}"
        
    def _get_cached_result(self, cache_key: str) -> Optional[Dict[str, Any]]:
        """
        获取缓存结果
        
        Args:
            cache_key: 缓存键
            
        Returns:
            Optional[Dict]: 缓存的搜索结果
        """
        try:
            # TODO: 从Redis获取缓存
            return None
            
        except Exception:
            return None
            
    def _cache_result(self, cache_key: str, result: Dict[str, Any]) -> None:
        """
        缓存搜索结果
        
        Args:
            cache_key: 缓存键
            result: 搜索结果
        """
        try:
            # TODO: 存储到Redis缓存
            pass
            
        except Exception:
            pass
        
    def _format_search_result(self, raw_result: Dict[str, Any], query: str) -> Dict[str, Any]:
        """
        格式化搜索结果
        
        Args:
            raw_result: 原始搜索结果
            query: 搜索查询
            
        Returns:
            Dict: 格式化的搜索结果
        """
        formatted_result = {
            'success': True,
            'query': query,
            'timestamp': datetime.now().isoformat(),
            'total_results': raw_result.get('total', 0),
            'results': [],
            'suggestions': raw_result.get('suggestions', []),
            'related_queries': raw_result.get('related_queries', [])
        }
        
        webpages = raw_result.get('webpages', [])
        for item in webpages:
            formatted_item = {
                'title': item.get('title', ''),
                'url': item.get('link', ''),
                'snippet': item.get('snippet', ''),
                'source': item.get('source', ''),
                'published_date': item.get('date'),
                'score': item.get('score'),
                'content_type': 'webpage'
            }
            formatted_result['results'].append(formatted_item)
        
        return formatted_result
        
    def _save_search_history(self, user_id: str, query: str, result: Dict[str, Any]) -> None:
        """
        保存搜索历史
        
        Args:
            user_id: 用户ID
            query: 搜索查询
            result: 搜索结果
        """
        try:
            # TODO: 保存到数据库
            pass
            
        except Exception:
            pass
            
    def _create_error_response(self, error_message: str) -> Dict[str, Any]:
        """
        创建错误响应
        
        Args:
            error_message: 错误信息
            
        Returns:
            Dict: 错误响应
        """
        return {
            'success': False,
            'error': error_message,
            'timestamp': datetime.now().isoformat(),
            'query': '',
            'total_results': 0,
            'results': [],
            'suggestions': [],
            'related_queries': []
        }


# 便捷函数
def search_web(query: str, user_id: Optional[str] = None, **options) -> Dict[str, Any]:
    """
    便捷的网页搜索函数
    
    Args:
        query: 搜索查询
        user_id: 用户ID
        **options: 搜索选项 (scope, include_summary, page, size)
        
    Returns:
        Dict: 搜索结果
    """
    service = SearchService()
    return service.search(
        query=query,
        user_id=user_id,
        scope=options.get('scope'),
        include_summary=options.get('include_summary'),
        page=options.get('page'),
        size=options.get('size')
    )


def get_suggestions(partial_query: str, limit: int = 5) -> List[str]:
    """
    获取搜索建议的便捷函数
    
    Args:
        partial_query: 部分查询字符串
        limit: 建议数量限制
        
    Returns:
        List[str]: 搜索建议列表
    """
    service = SearchService()
    return service.get_search_suggestions(partial_query, limit)